Crystal and molecular structure of bis(difluorophosphino)amine at –110 °C

Abstract

At –110 °C, crystals of NH(PF₂)₂ are monoclinic, with a= 8.69, b= 4.72, c= 12.08 Å, β= 98.3°(0.3% estimated standard deviations assumed), space group P2₁/n, and Z= 4. The structure has been refined to R 0.076 using 561 unique intensities obtained from microdensitometer measurements of the Weissenberg levels h0–4I taken with Cu-K_α radiation. The molecular structure approximates to C_2v symmetry with the following geometrical parameters: 〈P–N〉 1.667(10), 〈P–F〉 1.578(5)Å, P–N–P 120.7(4), 〈F–P–F〉 95.7(4)°. Although the hydrogen atom is not well located, the nitrogen co-ordination appears to be trigonal planar. There are weak intermolecular H … F interactions, and additionally one phosphorus atom is involved in P … F interactions. This phosphorus has three ‘normal’ bonds and two very long P … F contacts.